Chemistry / Unit 4 Chem 0669 worked example, 60 to 90 seconds
Calculating Heat from Bomb Calorimetry
The idea
Calculating heat from bomb calorimetry means adding the heat absorbed by the surrounding water to the heat absorbed by the bomb itself, since both together make up the calorimeter's full surroundings.
In practice
Burning 3.12 g of glucose inside a bomb calorimeter containing 775 g of water raises the temperature from 23.8 °C to 35.6 °C, and the steel bomb's own known heat capacity is 893 J/°C. Multiplying the water's mass, specific heat, and temperature change gives the water's heat gain; multiplying the bomb's heat capacity by that same temperature change gives the bomb's own heat gain. Adding these two contributions together gives a total heat release near 48.7 kJ for that single glucose sample.
Where people slip
Computing only the water's heat gain and quietly ignoring the bomb's own heat capacity understates the true heat the reaction actually released.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
- Nothing yet depends on this.
Something wrong in this lesson? Flag it · Sources for Chemistry